brainpopfandomcom-20200223-history
Mountains/Transcript
Transcript An image of a mountain range is shown. Text reads: The Mysteries of Life with Tim and Moby. MOBY: Beep. A robot, Moby, and a man, Tim, are shown hiking in a mountainous landscape. Tim is holding a map. Moby points at four different types of mountain peaks right next to each other, and Tim looks up. TIM: You got that right—that is a pretty unusual mountain range! One peak in the range is sharp and pointed, another is more rounded but has horizontal ridges down its sides, another has smoke coming out of a crater in the top, and another is rounded and looks smooth. Tim holds up a letter, which he then reads. TIM: Dear Tim and Moby, What can you tell me about mountains? From Jack. Mountains are one of the basic types of land forms. Almost onequarter of all land on Earth is covered in mountains, and they have a major impact on the environment. Four images are shown. The first image is of a grassy hillside. The second shows a valley with flat elevated land on both sides and a rocky mountain range in the back. The third image shows a desert landscape with some rock formations. The fourth image shows grassy flatlands. TIM: Most of the world’s major rivers are fed by melting ice and snow from mountains. A snowbank beside a body of water is shown. The sun shines on the snowbank, and melting snow slides down from the top of the bank and into the water. TIM: And because mountains form natural wind barriers, they impact climate and weather around the globe. One example of that is the Sierra Nevada range, in the western United States. Winds blowing in from the Pacific Ocean lose their moisture on the western side of the range. As a result, much of the land directly east of the mountains is desert. A map of the world is shown. The west coast of the United States is magnified to show the Sierra Nevada range and the desert land beyond it. MOBY: Beep? TIM: Well, mountains are classified based on how they form. The earth’s crust is divided into huge sections called plates. There are seven major plates and lots and lots of little ones. These plates move around very slowly, and that movement is called plate tectonics. Mountain ranges form where plates shift, pull apart, or push together. A map of the world is shown again. Dotted lines appear over both the land masses and the water, separating the entire map into thirteen pieces. Two plates are then shown rubbing against each other, one with an arrow pointing up as it slides one way and the other with an arrow pointing down as it slides the opposite way. A horizontal split screen is then shown. The bottom image shows two land masses pulling away from each other as water fills the space between them. The top image shows two land masses pushing together and forming a mound. MOBY: Beep. TIM: Lots of times you can tell how a mountain was formed just by looking at it! Four images are shown. The first image is of a land mass breaking vertically, one half moving downward and the other pulling upward. The second shows land pushing together and buckling to create a mound. The third shows a section of land being pushed upward out of the earth, breaking off from the land on either side of it. The fourth shows a volcano with a molten core. TIM: When tectonic plates converge toward each other, you get folded mountains. The Himalayas, in Asia, are a folded range that began to form about 45 million years ago, when the Indian plate collided with Asia. Folded mountains are shown. They are rounded and smooth. On top of this, the image of land pushing together and buckling is shown. A map shows the arrangement of the continents before the tectonic plates moved into their current positions. A roughly triangular land mass moves toward Asia, and a range of mountains, represented by arrowheads, appears where the two land masses meet. MOBY: Beep? The mountain peak with horizontal ridges down its sides is shown. TIM: Those sharp peaks and ridges are signs of upwarped mountains. They form when forces inside the Earth push up parts of the crust. Over time, the rock is exposed and weathered. Many parts of the Rocky Mountains are upwarped. Over the image of the peak with horizontal ridges, a section of land breaking away on both sides as it is pushed out of the earth is shown. Two craggy peaks of the Rocky Mountains are shown. TIM: Faultblock mountains are made of huge tilted blocks of rock separated by faults. A fault is a large crack in the rock where movement happens. Most faultblock mountains, like the Basin and Range region of the western United States, form where tectonic plates pull apart. The jagged mountain peak is shown. Over this, a land mass breaking vertically with one half pulling upward is shown. A mountain range with sharp peaks is shown behind a desert. MOBY: Beep! Moby points to the peak with the crater spewing smoke. There is molten rock inside the crater. TIM: When molten magma is forced through cracks in the earth’s crust, it cools in layers. The layers form a cone shape over time—that’s a volcanic mountain. Over the image of the cratered peak, an animation shows layers of magma and rock building into a peak with a molten magma core. TIM: The volcanic ocean ridge system is easily the longest mountain belt in the world, stretching all around the planet! A map of the world is shown, and the ocean ridge system is highlighted. It goes up through the Pacific Ocean, up through the Atlantic, and through the Indian Ocean and Arabian Sea. TIM: As these volcanoes push up magma and form new land, the plates on either side of them spread apart. Unfortunately, all that underwater volcanic activity can cause earthquakes and tsunamis. Magma is shown flowing under broken pieces of rock. Two more images are shown. The first is of a crack in the earth’s crust, and the second is a tsunami wave crashing through palm trees. TIM: Okay, well, that’s it for mountains. Have you got other cool things to show me? MOBY: Beep. Moby pulls off his head. Tim stares at him. TIM: No, um, I meant, like cool ... natural stuff around here, like rock formations or ... uh. Moby holds his detached head in his arms and stares blankly at Tim. TIM: Never mind. Tim gives up and goes back to looking at his map.Category:BrainPOP Transcripts